Turbo-compressor and capacity control method therof

摘要

A turbo-compressor comprises a compressor main body for compressing an operation fluid, an inlet guide vane apparatus being provided on a suction side of the compressor main body and having guide vanes, and a blow-off valve being provided in a discharge said compressor main body. An opening of the blow-off valve is variable. A pressure detector is provided on the discharge side of the compressor. At least any one of a time-period and a number of times of operations of the inlet guide vane apparatus is memorized in a memory, when it is operated at an inlet guide vane opening, being equal or less than a setting limit. A controller controls the blow-off valve and the guide vanes based on the values which are memorized in the memory.